This invention relates generally to protective devices for use with medical needles and the like to safeguard against accidental and/or unauthorized needle use. More particularly, this invention relates to an improved yet relatively simple and economical safety device for protecting medical personnel and the like against accidental contact with medical needles and/or exposure to potentially hazardous patient fluids thereon in the course of normal needle handling and use. Moreover, this invention relates to a simplified and reliable locking arrangement for preventing accidental or unauthorized re-use of a used medical needle.
Medical needles are widely used by the health care industry in the course of patient diagnosis and/or treatment. Such medical needles commonly comprise an elongated hollow metal tube mounted within and protruding from an appropriate support structure, such as a syringe barrel, a support hub for attachment to a syringe barrel, or other structures such as fittings adapted for attachment to fluid specimen containers of the type used to obtain blood samples, etc. A forward end of the metal tube is shaped to define a sharp point adapted for transcutaneous insertion into the body of a patient for purposes of drawing patient fluids for analysis, or for injecting medication or other fluids into the patient. Modern medical needles are most commonly provided in a presterilized package intended for disposal after a single use, with a removable plastic cap typically mounted onto the support structure in a position covering the needle to safeguard against accidental contact with the needle prior to use. After the medical needle is used, the cap is desirably re-installed to re-cover the needle prior to discard into a suitable waste receptacle.
The handling and use of medical needles requires extreme caution to prevent accidental needle stick injuries. More specifically, considerable attention and manual dexterity are required to avoid occasional infliction of needle injuries upon health care workers and other unintended persons. When such needle sticks occur prior to the intended use of the needle, sterility of the medical needle is compromised. Moreover, and more importantly, post-use needle sticks expose persons other than the patient to blood-borne diseases and other organisms which might be present on a used needle. For example, it is well recognized that a variety of contagious and potentially dangerous diseases such as hepatitis, acquired immune deficiency syndrome (AIDS), and others can be transmitted by contact with patient body fluids present on a used medical needle.
Moreover, in recent years, discarded medical needles have been the subject of unauthorized re-use by persons involved in illegal or illicit drug use. Prevention of such unauthorized re-use has become extremely desirable to curb the flow and use of illegal drugs, and further to prevent uncontrolled spread of communicable diseases resulting from contact with contaminated needles.
In the prior art, a variety of devices and systems have been proposed for protecting medical personnel against accidental contact with medical needles, and/or for preventing unauthorized re-use of medical needles. Some f these devices have utilized sleeve-type structures mounted about the barrel of a hypodermic syringe for extension or retraction movement about the syringe barrel for respectively covering or exposing a hypodermic needle. Such sleeve-type structures have normally included complex tab and track mechanisms for guiding the sleeve between the extended and retracted positions, with some designs intending to lock the sleeve in the extended position after needle use. However, these devices have generally exposed the needle to view and potential access through a relatively large open end of the sleeve when said sleeve is in the retracted position. See, for example, the devices described in U.S. Pat. Nos. 4,702,738; 4,631,057; 4,737,144; 4,425,120; and 4,723,943. Other protective devices have envisioned needle guards With narrow apertures for passage of a medical needle during normal use, after which the guard is displaced beyond the needle point and manipulated to a position intended to minimize the chances of needle reinsertion through the guard aperture. See, for example, U.S. Pat. Nos. 4,725,267 and 4,735,618. However, this latter group of devices has been characterized by relatively complex mechanical arrangements which have not positively locked the medical needle against access or reuse.
There exists, therefore, a significant need for further improvements in protective devices and systems for preventing accidental and/or unauthorized contact with medical needles, particularly with respect to the provision of a simple, economical, and easy-to-use device which minimizes the risk of accidental needle stick injuries while additionally rendering a medical needle substantially inaccessible after use. The present invention fulfills these needs and provides further related advantages.